50 1.8 Backfocus...?!

So i just picked up this used 50mm 1.8 and i noticed that while using center focus point only, non of my shots really seemed in focus. Thinking maybe i was just moving around too much after getting focus lock, i did some tests and came up with these pretty disappointing results:

Both were shot on a tripod with MLU at ISO 100 with +1 contrast, sharpness, and saturation, these are 100% crops and the red box shows the point of focus (focus point was specifically over the first "1" in "1319", and the subject is closer at the right and farther away at the left).

Look like a bad copy to any of you, or am I a complete idiot?? :\ And does anyone know if Canon will service used lenses? I dont have the warranty card as of now either, but might be able to get it, MAYBE. ...Man, pretty disappointing for my first prime lens, especially after using L glass zooms. Even for an el Cheapo, im pretty disappointed in the image quality, especially the massive aberrations at f1.8 (as you can see)... I assume thats normal for this lens though? Any insight from you all would be extremely appreciated. Thanks!!